My favorite is the Medic gameplay wise, I'm only so-so at PC shooters so I like being a priority to protect, and having a Heavy with me as a bodyguard, BioShock style.

Personality wise I think my favorite would be the Spy, just for his line in the Meet the Spy video.

"What are you, the president of his fanclub?"

"no...zat would be...YOUR MOTHER!"

"Destiny shall draw the lightningDown from heaven, roll it's thunderFar across the sea to where I waitUpon the Shore of Wonder onThe day the sky is Opened andThe tree is torn asunder."-Epitaph of Cygna Threadbare